import Control.Monad (replicateM)

solve :: Int -> [[Int]] -> Int
solve n rs = foldr (\[x, y] z -> f x y z) n rs where
    f x y z | x == z    = y
            | y == z    = x
            | otherwise = z

main = do
    n <- readLn :: IO Int
    m <- readLn :: IO Int
    pqs <- map (map read . words) <$> replicateM m getLine
    print $ solve n (reverse pqs)